Reamer and honer for wrist pin bushings



Jan. 6, -1953 c. 1 CLARK REM/1ER AND HoNERHFoR WRIST PIN BusHINGs Filed July 29, 1947 2 SHEETS-SHEET l ecf/ CV/ar/r WMM/m aww',

Jan. 6, 1953 Q CLARK REAMER AND HONER FOR WRIST PIN BUSHINGS 2 SHEETS-SHEET 2 Filed July 29, 1947 620// ll. Var/f Patented Jan. 6, 1953 REAMER AND HONER FOR WRIST PIN BUSHINGS Cecil L. Clark, Three Rivers, Calif. Application July 29, 1947, Serial No. 764,333

3 Claims.

relates to an adjustable reamer and honer for the bushing of wrist pins.

The connecting rod of an internal combustion engine is pivotally fastened to its piston by a wrist pin. The end of the connecting rod is tted with a bronze bushing, and the central portion of the wrist pin passes through the bushing. The ends of the wrist pin are accommodated in drilled holes in the skirt of the piston. The wrist pin may be anchored to either the piston or the connecting rod so as to be free to turn with respect to the other, or may be full floating to turn freely with respect to both.

It is, of course, essential that the wrist pin t accurately with respect to the bushing. When a bushing is rst reamed, it contains numerous hair lines or high spots, and the iitting of the wrist pin in the bushing is based on these hair lines. Consequently, when the pin is inserted in its bushing, it engages only the hair line. The maximum bearing surface for the pin under such conditions does not ordinarily exceed a fraction of the entire bearing surface of the bushing. This necessarily results in quick wearing of the bushing, and this causes knocks, rattles, and other objectional conditions which are antagonistic to high vefficiency operation of the engine.

It is a principal object of this invention, therefore, to provide a tool for giving the bushing a true and smooth bearing surface. More particularly, this tool is designed to ream and hone the bearing surface of the bushing to result in a smooth and highly polished surface. This tool is operable by a lathe or electric drill, and is furthermore adjustable to provide for diierent sizes of bushings.

A preferred embodiment of the invention is illustrated in the accompanying drawings, but it is understood that modifications may be made therein without departing from the spirit of the invention as hereinafter claimed.

Figure 1 is a front elevation of the new and improved tool, shown in conjunction with the bushing of a connecting rod, some of the parts being shown in section.

Figure 2 is another front elevation of the tool, some of the parts thereof being shown in section.

Figure 3 is transverse vertical section, on an enlarged scale, taken through the line 3-3 of Figure 1.

Figure 4 is a side elevation of a device for adjusting the tool.

Figure 5 is a front elevation of another adjusting means.

Y This invention Figure 6 is a front elevation of an adapter for driving the tool from the chuck of the lathe or drill press.

Figure 7 is an enlarged transverse section of the tool when an abrasive cloth is used therewith for honing purposes.

Figure 8 is a perspective view of thev abrasive cloth.

The device comprises a cylindrical body I0 provided with several pairs of slots II. These slots II are radial, and extend longitudinally of the body I0. A central portion I2 of the body III divides the slots II into pairs. Four such pairs are shown, but it is obvious that more or fewer may be employed. Each of the slots Il is adapted to contain a vane I5, that is movable radially of the body I0, for a purpose to be described more particularly hereinafter.

Each of the vanes I5 is provided with two notches I6 on its outer surface, adjoining its end, and an annular coil spring I8 encircles all the vanes I5 at the notches I6 and keeps the vanes I5 in place on the body I0.

The central portion I2 of the body ID has a plurality of angular cam surfaces 20, one such surface being provided for each of the vanes I5, and the inner ends of the vanes I5 are formed to complement the angular surfaces 20. Consequently, as the vanes I5 are pushed inwardly toward the central portion I2, the adjacent ends of the vanes I5 will ride upwardly on the cam surfaces 2|). A similar cam surface 2l is provided on a portion of the body II) adjacent the outer ends of the vanes I5, and the vanes I5 adjacent thereto are mated. Consequently, translation of the vanes I5 toward the central portion I2 will cause the vanes I5 to ride upwardly on the cam surfaces 26 and 2| in such a way that the vanes I5 remain parallel to the periphery of the body I0.

The outer ends of the body I0 are extended to form sleeves 23 and 2d. The inner bore of each of the sleeves 23 and 24 is threaded to receive an adjusting screw 26 and 21, respectively. The inner end of each of the screws 26 and 21 is adapted to bear against the ends of the vanes I5, to produce the axial and radial movement of the vanes I5 with respect to the body Il), hereinbefore mentioned. Each of the adjusting screws 26 and 21 may be provided with a knurled handle 28 and a lock nut 29 to facilitate manipulation of the screws 26 and 21.

The central portion I2 of the body I6 accommodates a radial reamer 3|, the reamer 3l being normally urged upwardly by a spring 32 seated in a slot 33 in the central portion I2 of the body -fit for the wrist `pins 3 I 0. The reamer 3| may be locked in position by means of a set screw 35.

Let it be assumed that it is desired to reain the bushing 4E of a connecting rod 4 i. Let the righthand varies I5 of the structure shown in Figures l and 2 be called the leading vanes and the left-hand vanes be called the follower vanes. Then the adjusting screw 21 is rotated until the leading vanes I5 can enter the bushing 40 to act as leading guide vanes. The follower guide vanes I are then adjusted to indicate the size of the bushing el afer it has been reamed. To obtain this adjustment, two wrist pins 42 and 43 are mounted between two parallel surfaces 44 and 45, as indicated in Figure 4 of the drawings, a pair of clamps tl and t being ,one way of insuring parallel relationship between the surfaces 44 and :35 about the wrist pins 42 and .43. The follower end of the body It is then inserted between the parallel surfaces 44 and .45., andthe adjusting screw 25 ,manipulated until the follower vanes I5 engage the parallel surfaces `fljl yand 4.5, as indicated in Figure 4. In this position, the follower varies I5 will indicate the correct spacing desired in the bushing 463 to provide the proper .42 vand d3. Then, as indicated in Figure 5, a straight edge 4s may be positioned Aover the follower vane I5, and the .,reamer 3l adjusted until it is in ,proper align- :ment `with the follower vanes t5, .after which .the reamer SI maybe lloelfted irl-position by Ameans `of the set screw 13:5. Alternately, .the reamer 3l and followervanes I E may be positioned `and.adjusted by `means of a micrometer.

The sleeve 23 of the body le may then be inserted ina chuck 5I, which is driven by the .shaft 52 of a lathe ordrill press, .and the .sleeve 23 is locked in .position in the chuck -5.I by means of a locking screw 53. The bushing .4% and connecting `rod vlil are slipped over the right-hand ,end of the body I Il, so that the .leading vanes lI5 may enter the bushing fifi. The leading `varies liserve as guides, until the bushing .im contacts .the reamer 3l. The `reamer -BI reams .out .the interior ofthe 'bushing the machined portion of the bushing se sliding over the .follower .vanes I5 on the left-'hand portion the -body IE). The .springs I8 arein the notches I6 Aand do not project above the surfaces of the vanes If'5.

After fthe bushing :es has been reamed, the -reamer 3| .may be removed, .and all the -vanes l5 may be ereplacedby similar blades having a honn ingsurface ed. The b shing may fthen be `positioned over the 4.body until the inner .surface thereof .has been proper-.ly .honed by `the honing ,surfaces Si) on the blades i6. If desired, the leading :blades It may be retained, .and only :the .follower .blades l5 be .replaced .by the )honing blades, or the procedure may be reversed.

Proper allowance must be `made for the amount of metal removed by the honing process,.and `for this reason :the reamer 3S and-,the follower `vanes I5 may .be .set ,initially at a fraction of an inch below the Idesired diameter, for ,.example, one half `ofone thousandth of an inch.

:Instead of utilizing blades I5 `,with a -Yhon-ing .surface Sli, the follower` vanes I5 or -both `the follower and the leading bla-des v`I?, maybe removed entirely, and an abrading Vcloth 65 wrapped `around the body Ill. Theabrading cloth, shown in Figure 8 of the drawings, is `lprovided with a .metallic channel 65 along ene edge, Vand this ,channel Vt6 is accommodated in a longitudinal slot 57i :in lthe body Iii.

may be wrapped around theblades Or, if desired, :the abra-v ,vanesof feach set )being l,mounted fl I5, as indicated in Figure 7 of the drawings, and the channel 6E tucked into the slot 61 to hold the cloth B5 in position.

To assist the reaming operation, the central portion I2 of the body I6 may be provided with a channel I0 to catch the chips, and the main" portion of the body I0 may be provided with another channel I'I extending longitudinally thereof, for a similar purpose.

What is claimed is:

1. A rearning tool comprising a cylindrical body, there being at least one pair of radially disposed slots extending longitudinally from each end of said body and terminating at a point spaced from the central part of the latter, a sup` port positioned in the space between said pairs of slots, areamer mounted within said support transversely of said body for extensile and retractile movement, with respect to the latter, resilient means operatively Lconnected to said reamer for eecting -extensi-le movement rof the latter, a vane positioned within each of the slots of one pair and forming a set of leading vanes, another vane positioned within 4each `of the slots of lthe other pair and forming a set .of following vvanes, the varies of `each set being mounted for sliding movement radially of said body, and means carried by said body for effecting the Vradial AInovement of leach set of varies independently.

l2. A reaniing tool comprising `a cylindrical body, there being Vat least ,one pair of radially ydisposed slots extending longitudinally from each end of said body and terminating ,at a point spaced from the central part of the latter, a support positioned .in the space between said pairs of slots, a ,reainer mountedwithinfsaidsupport transversely ,of said body for extensile and `retraetile movement, ,with respect to vthe latter, resilient means operatively Aconnected to said rearner for 4effecting `ex'tensile V.movement of the latter, a vane positioned Within each lof rthe slots `of one pair and forming a 4set ,of Vleading vanes, another .vane positioned .within 4,each Aof the slots ofythe other pair and `forming :a fset ,of Qllow-ing vanes, the

,for sliding-.movement Vradially of said'bQdy, and :separate rotatable means carried by each end of said body and engageable with fthe adjacentends ,of the vanes for .effecting the radial ,movementgof Vlthe latter.

43. A.reamingtoolcomprising acylindrical body, .there .being .at least one -pair of radiallydisposed slots vextending :longitudinally from each end of .said-:body .andterrni-nating at a Lpoint spaced from l'fhe .central ,part ,of the latter, Aa ysupport posi- :tionedfin the space `between sai-d `pains of slots, said support being provided with two pairs .o f cam urfacesarranged in opposedrelation with-respect Ito eachother ,and in aligned relation iwith respect .to the adjacent ends of said ,pairs .of slots, a reamer positioned transversely orsaid body and mounted within said `sumnort for extensile .and retractile movement with ,respect to the latter, resilient .means `operatively connected .to said ,reamer for effecting ,.extzensile .movementof the latter, a vane positioned withineachof the slots `of .one pair .and :forming a set of leading yenes, .another vane positioned within-each of the Aslots of the other pair and forming a set of following vanes, the vanes of each set being mounted for sliding :movement 4lungitudinally of the .slots of each pair, said vanes having one end Abearing against the ,cam .surfaces vpreyided iadjacentthe ends of said pairs of slots to thereby .produce `a radial movement with respect to .said body .upon sliding movement of the vanes of each .set .longitudlnally of the slots of each pair, and means Number bearing against the other end of the Vanes of 1,473,245 each set for effecting said sliding movement of 1,485,930 the latter. 1,491,179 CECIL L. CLARK. 5 1,824,494 1,909,347 REFERENCES CITED 2,038,611 The following references are of record in the 21083300 flle of this patent: 233,132 UNITED STATES PATENTS lo Number Name Date Number 496,253 Federschmidt Apr. 25, 1893 442,329 1,362,871 Kelly Deo. 21, 1920 Name Date Miller Nov. 6, 1923 Howind Mar. 4, 1924 Vedoe Apr. 22, 1924 Olson Sept. 22, 1931 Hall May 16, 1933 Simonson Apr. 28, 1936 Rose et al June 8, 1937 Wommer May 12, 1942 FOREIGN PATENTS Country Date Great Britain Feb. 6, 1936 

